Multicontour Seat Problem W210
 

My 2001 W210 E55 has the multicontour seat option. This appears to work via inflatable air cushions built into the front seats. I noticed this feature wasn't working recently and then last week it started working again. This week it stopped working once more. I don't see any mention of a specific fuse in the fuse box chart for this option. Has any one worked on this system? Could it be a vacuum problem somewhere? Any ideas would be appreciated.